Data from: A modelling framework to assess the effect of pressures on river abiotic habitat conditions and biota

River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability / ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes) on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact research as well as river restoration and management.

河流生物群落（River biota）受到全域河段尺度压力的影响，但当前绝大多数预测河流生物群落的研究方法，均聚焦于河段或河段尺度的过程与栖息地。此外，此类方法未考虑会影响栖息地状态的长期地貌变化。本研究进一步开发并验证了一套建模框架，用于评估不同空间尺度的压力对河段尺度栖息地状态与河流生物群落的影响。研究采用生态水文模型与一维水动力模型（1D hydrodynamic models），对流域尺度（catchment scale）的流量与水质，以及研究河段下游端的水位进行预测。通过经验河道形态方程、河湾迁移模型与二维地貌动力学模型（2D morphodynamic models），对河段的长期地貌形态开展模拟。借助二维水动力模型预测研究河段内的水流与底质条件，并通过新型栖息地模型评估此类栖息地的适宜性。此外，本研究还开发了针对鱼类与大型无脊椎动物（macroinvertebrates）的扩散模型，用于评估其重新定殖潜力，并最终对比栖息地适宜性与物种定殖此类栖息地的可及性及定殖能力。研究以德国北部的低地特雷内河（lowland Treene River）为研究对象，通过对比实测与模拟得到的环境条件，验证了该建模框架的适用性并评估了模型性能。从技术层面而言，不同模型的串联已可实现，但未来若要推广应用，仍需开发适配所有建模步骤的开源软件，以实现模型的全自动化运行。未来研究方向包括长期地貌动力学的物理模拟、生物群落（例如大型水生植物（macrophytes））对非生物栖息地条件的反馈作用、物种间相互作用，以及大型无脊椎动物的水力栖息地适宜性与扩散能力相关的实测数据补充。该建模框架具有良好的灵活性，可兼容新增模型，并可用于探索各类研究与管理问题，例如气候影响研究、河流修复与管理等领域。